Trios
Many Legendaries can comfortably be fit together within groups of trios, typically with a trio leader. A handful of them are a part of many groups whether officially by the Creator or unofficially by mortals. Creation Trio Leader: Arceus Members: Dialga, Palkia, and Giratina This trio is meant to uphold the universe and all that happens within it. They very rarely, if ever, interact with others and few Legendaries, let alone mortals, currently even know of their existence. The Priests of Arceus claim that Dialga, Palkia, and Giratina are in fact fragments or Arceus, and thus one Pokemon. Creation's Assistants Leader: N/A Members: Celebi, Hoopa, Shaymin Unofficial Member: Phione (F) This trio is meant to act as a bridge between the higher gods' aspects and the mortals on earth. They are tasked with helping their creator with whatever they need help doing, and uphold their respective aspects when the Creation Trio is unable to. Phione (F), born to Celebi and Manaphy, was made a member of this trio because of her ability to use time travel, her fearless and brave attitude, and willingness to help out in any way she can. World Shapers Leader: Regigigas Members: Groudon, Kyogre, Rayquaza This trio is meant to form the landscape of the world. Sometimes called the Titans or the Ancient Ones. Should the trio fight, Regigigas is meant to stop them. Weather Trio Leader: Rayquaza Members: Groudon, Kyogre This unofficial trio was recognized by mortals prior to Regigigas being placed on the earth. Despite Rayquaza being the youngest of the three, she is seen as the leader as she often tries to calm their fighting, even if accidentally egging it on or having no interest in doing so. Humanity Leader: '''Arceus '''Members: Mesprit, Azelf, Uxie This trio is meant to uphold the flow of emotion, willpower, and knowledge. Each member is tasked with weaving their own sphere which influences the mortals and the rest of the universe. Golems Leader: Regigigas Members: Regice, Regirock, Registeel Having been created by Regigigas, this trio doesn't often come together, but are recognized as a trio because of their shared strengths, appearances, and obligation to help Regigigas whenever it so needs. Water Assistants Leader: Kyogre Members: Lugia, Manaphy, Phione (M) This trio came together long before it was considered one, but wasn't officially recognized until Manaphy was born to Lugia and Kyogre. The members are meant to serve as assistants to Kyogre, help monitor the ocean, and report to him anything that seems odd. Land Assistants Leader: Groudon Members: Ho-Oh, Heatran (F), Heatran (M) This trio didn't come together until the twin Heatran were born to Groudon and Ho-Oh. The members are meant to serve as assistants to Groudon, help monitor the land, and report to her anything that seems odd. Sky Assistants Leader: Rayquaza Members: Landorus, Thundurus, Tornadus This trio was the first assistant trio. They are meant to serve Rayquaza, help monitor the sky, and report to her anything that seems odd. Forces of Nature/Wishmakers Leader: Landorus Members: Thundurus, Tornadus An unofficial trio formed by Landorus, Thundurus, and Tornadus during their reign as terrible monsters on earth. They continue to go by this today if it's to do with something that does not involve Rayquaza at all. See: dealings with mortals, the black market. The Wind Leader: N/A Members: Latias, Latios These twins were born to Lugia and a long-passed Flygon. Weather Birds Leader: Lugia Members: Articuno, Zapdos, Moltres This trio is meant to bring winter, spring, and summer across the world. Without them the weather would become disturbed and chaotic. Legendary Beasts Deceased Life and Death Leader: N/A Members: Xerneas, Yveltal, Zygarde This trio is meant to keep the flow of life and death in check. Their own assistants are the reapers and --. Should the balance be disturbed Zygarde will collect the 10 cells to fulfill the role it needs. Lunar Dreams Leader: N/A Duos Members: Cresselia, Darkrai From their dream realm this duo is meant to understand the mind in extreme detail in order to weave dreams and nightmares. The Three Musketeers Leader: Cobalion Members: Terrakion, Virizion This trio is meant to interact directly with and protect the mortals across the earth.